Each day a different image or photograph is featured, with an
accompanying caption, which deals with various topics in Earth Science.

New Madrid Seismic Zone and the Mississippi River

This Landsat 7 image acquired on October 26 of this year is dominated by the Mississippi River as it flows through Tennessee and Missouri in the vicinity of the New Madrid seismic zone, site of one of the largest earthquakes to rock North America in recorded history. In 1811-1812, the New Madrid earthquakes rang bells in Boston and temporarily reversed the flow of the Mississippi River. Margaret Guccione, a University of Arkansas researcher has linked shifts in the course of the Mississippi River and its tributaries to earthquakes and landscape changes in the New Madrid seismic zone, helping to more accurately date past earthquakes. Guccione has examined several loops of the Mississippi River in this region that have been abandoned by the river in the past 2,400 years and used radiocarbon techniques to date the organic matter found in sediments at different levels. Some of this sediment had rapidly accumulated because of the shift in drainage direction that dates to A.D. 1470. This date correlates with other geologic estimates for a large quake in the New Madrid Seismic Zone. Scientists today have focused their efforts on determining the frequency and intensity of past earthquakes to better determine the possibility of future quakes.